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Slab Horizontal Subduction and Slab Tearing Beneath East Asia
Author(s) -
Ma Pengfei,
Liu Shaofeng,
Gurnis Michael,
Zhang Bo
Publication year - 2019
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2018gl081703
Subject(s) - geology , subduction , slab , slab window , tearing , seismology , mantle (geology) , seismic tomography , tectonics , clockwise , discontinuity (linguistics) , geophysics , plate tectonics , oceanic crust , rotation (mathematics) , geometry , mathematical analysis , physics , mathematics , thermodynamics
The present‐day architecture of subducted slabs in the mantle as inferred from seismic tomography is a record of plate tectonics through geological time. The unusually large slab that lies nearly horizontally above the 660‐km mantle discontinuity beneath East Asia is presumably from subduction of the Pacific plate. Numerical models have been used to explore the mechanical and geophysical factors that contribute to slab stagnation, but the evolution of this horizontal structure is not fully understood because of uncertainties in the plate‐tectonic history and mantle heterogeneity. Here we show that forward mantle‐flow models constrained by updated tectonic reconstructions can essentially fit major features in the seismic tomography beneath East Asia. Specifically, significant tearing propagated through the subducted western Pacific slab as the Philippine Sea plate rotated clockwise during the Miocene, leading to internal slab segmentation. We believe this tearing associated with Philippine Sea plate rotation also affects the horizontal configuration of slabs.